The present invention relates to a method of manufacturing a magnetic disk device, and more particularly, to a method of manufacturing a magnetic disk device having a head gimbal assembly excellent in moving performance.
The head/slider installed on the suspension assembly of a magnetic disk device moves to the required track while flying slightly over the surface of the magnetic disk since its air-bearing surface is assigned lifting force from the air stream generated on the surface of a magnetic disk which rotates. In order for the head/slider to have sufficient moving performance to always maintain in the required range the spacing between the head and the magnetic disk surface, it is an important factor that the static attitude of the head/slider with respect to the magnetic disk surface before the head/slider starts to fly should be as close as possible to an ideal value. In general, the static attitude of the head/slider is defined by a static roll angle or roll static attitude (RSA) that is the angle of rotation around the longitudinal axis of the suspension assembly, and a static pitch angle or pitch static attitude (PSA) that is the angle of rotation around an axis vertical to the longitudinal axis of the suspension assembly after the head/slider has moved past a dimple contact point (DCP). A conventional method of correcting PSA and RSA to bring the static attitude closer to an ideal one has been by applying mechanical bending or twisting force to a head gimbal assembly (HGA) with a head/slider installed on a suspension assembly. A method of correcting PSA and RSA by irradiating laser light has also been proposed.
Patent Document 1 (Japanese Patent Laid-Open No. 2002-74630) discloses a system for controlling the attitude of a suspension by irradiating laser light. In the invention of Patent Document 1, a line number, a line starting point, a line angle, laser intensity, a shot time interval, and the number of shots are assigned as conditions to various linear-correction lines and then the pitching angles and rolling angles obtained when samples actually suffer deformation when irradiated with laser light in various combinations of the conditions are measured to create a linear correction table. After the creation of the table, the attitude of the suspension is corrected during an actual workpiece correction phase by irradiating light in accordance with a correction recipe created by sequentially searching the linear correction table for the correction line that forms the angle closest to a target angle after correction from such a measuring angle as shown in FIG. 12 of Patent Document 1.
Patent Document 2 (Japanese Patent Laid-Open No. 2004-82161) discloses a technology for irradiating the required laser shot regions with laser light of the required length and shape and bending both the section of a suspension that is to be subjected to load-bending, and the section to be adjusted in angle. In the invention of Patent Document 2, the relationship between the irradiation of the laser light and the displacement of the section to be subjected to load-bending is acquired experimentally or by simulation in order to acquire the amounts of thermal deformation due to the laser light beforehand for each laser shot region. Irradiation patterns of the laser light are registered in a database as the shot characters showing a more specific example of the above relationship.